Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 Subaru WRX BaseFACTORY OEM SERVICE PROCEDURE
Section 11 (Engine Cooling System (2.5L)): General Description: Specification
WARNING: This page is about a different variant/trim than selected.
| Cooling system | Electric fan + Forced engine coolant circulation system | ||||
| Total engine coolant capacity L (US qt, Imp qt) | Approx. 7.7 (8.2, 6.8) | ||||
| Water pump | Type | Centrifugal impeller type | |||
| Discharge performance | Discharge rate L (US gal, Imp gal)/min | 200 (52.8, 44.0) | |||
| Pump speed - Discharge pressure | 6, 000 r/min - 225.4 kPa (23.0 mAq) | ||||
| Engine coolant temperature | 80°C (176°F) | ||||
| Impeller diameter mm (in) | 76 (2.99) | ||||
| Number of impeller vanes | 8 | ||||
| Pump pulley diameter mm (in) | 60 (2.36) | ||||
| Clearance between impeller and pump case mm (in) | Standard | 0.5 - 1.5 (0.020 - 0.059) | |||
| Thermostat | Type | Wax pellet type | |||
| Starting temperature to open | 76 - 80°C (169 - 176°F) | ||||
| Fully opens | 91°C (196°F) | ||||
| Valve lift mm (in) | 9.0 (0.354) or more | ||||
| Valve opening size mm (in) | 35 (1.38) | ||||
| Radiator fan | Motor input | Main fan W | 160 | ||
| Sub fan W | 160 | ||||
| Fan diameter/Blade | Main fan | 320 mm (12.6 in)/9 | |||
| Sub fan | 320 mm (12.6 in)/11 | ||||
| Radiator | Type | Down flow | |||
| Core dimensions | Width x Height x Thickness mm (in) | 687.4 x 340 x 16 (27.06 x 13.39 x 0.63) | |||
| Pressure range in which cap valve is open | Coolant filler tank side kPa (kg/cm2 , psi) | Positive pressure side | Standard | 93 - 123 (0.95 - 1.25, 14 - 18) | |
| Limit | 83 (0.85, 12) | ||||
| Negative pressure side | Standard | -1.0 --4.9 (-0.01 --0.05, -0.1 --0.7) | |||
| Radiator side kPa (kg/cm2 , psi) | Positive pressure side only | Standard | 122 - 152 (1.24 - 1.55, 18 - 22) | ||
| Limit | 112 (1.14, 16) | ||||
| Fins | Corrugated fin type | ||||
| Reservoir tank | Capacity L (US qt, Imp qt) | 0.45 (0.48, 0.40) | |||
| Recommended materials | Item number | Alternative | |
|---|---|---|---|
| Engine coolant | SUBARU SUPER COOLANT (concentrated type) | - | - |
| SUBARU SUPER COOLANT (diluted type) | K0670Y0001 | ||
| Water for dilution | Distilled water | - | Soft water or tap water |
| Cooling system protective agent | Cooling system conditioner | SOA345001 | - |
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.